Thank you for your support and your valuable comments to Electricity News over the years. In this issue, we invite popular singer Shiga to review with us the different grades of electrical work for registered electrical workers and electrical product safety.
Some electrical workers are confused about how the work they are permitted to carry out is differentiated even after they have been registered. For example, a Grade B electrical worker may be carrying out Grade C electrical work without knowing that he is breaching the law. The main feature article of this issue clarifies the scope of each grade of electrical work with wiring diagrams and illustrations, and explains the difference between Grade A, Grade B and Grade C electrical work to ensure you have a better understanding.
Another feature in this newsletter examines the issues of electrical product safety, including electromagnetic and LED lamp safety standards.
Shiga
Acknowledgement: Warner Music
Feature Article 1 - Different Grades of Electrical Work for Registered Electrical Workers
Under the Electricity Ordinance, an electrical worker shall carry out electrical work commensurate with the grade as specified on the certificate of registration. In accordance with the Electricity (Registration) Regulations, electrical work can be classified into 5 grades:
| Grade | Scope of Work |
|---|---|
| A | Low voltage fixed electrical installation that has a maximum demand not exceeding 400A |
| B | Low voltage fixed electrical installation that has a maximum demand not exceeding 2500A |
| C | Low voltage fixed electrical installation of any capacity |
| H | High voltage installation |
| R | Fixed electrical installation of specified type |
Grade A, B and C electrical work is differentiated according to the maximum demand of the electrical installation. For buildings in general, the maximum demand of an electrical installation is the total loading of the fixed electrical installation approved by the power company.
Grade A electrical work covers electrical installations in old buildings that have a maximum approved loading not exceeding 400A.
Figure 1: Grade A electrical installation
Grade B electrical work covers fixed electrical installations in buildings whose electricity is supplied by the power company through a group of independent transformers.
Figure 2: Grade B electrical installation
Grade C electrical work covers electrical installations whose power comes from a group of independent power source that exceeds 2500A or groups of power source each not exceeding 2500A but have an approved loading that exceeds 2500A in aggregate.
Figure 3: Grade C electrical installation
Registered electrical workers must ensure that they have already registered for the relevant grade of electrical work before they can engage in such work, including issuing Work Completion Certificate (WR1) or Periodic Test Certificate (WR2). Registered electrical contractors must also ensure that the registered electrical workers they employ will not engage in electrical work that they are not entitled to carry out. Anyone who breaches the above regulations commits an offence and is liable to a maximum fine of $100,000 and 6 months imprisonment.
Household electrical products supplied in Hong Kong are regulated by the Electrical Products (Safety) Regulation (the Regulation). According to the requirements of the Regulation, the supplier of a household electrical product in Hong Kong must make sure that the product has a valid certificate of safety compliance at the time when it is supplied in Hong Kong. For your easy reference, EMSD has published the Guidance Notes for the Electrical Product (Safety) Regulation, which has also been uploaded onto the EMSD web page. Paragraph B8 under Part III of the guidance notes explains the detailed requirements of the Certificate of Safety Compliance, while paragraph CI 1.2 sets out the international safety standards that some common electrical products must comply with. With new generations of electrical products appearing on the market in a shorter time than ever before, you are advised to refer to the web page of the International Electrotechnical Commission (IEC) at http://www.iec.ch/dyn/www for the safety standards of products that have not been listed in paragraph C1 1.2.
In accordance with the Regulation, household electrical products are classified into prescribed products and non-prescribed products. Prescribed products must comply with the requirements of the international basic safety standards, as well as the specific safety specifications in Schedule 2 of the Regulation. At present, prescribed products include plugs, adaptors, lamp holders, flexible cords, extension units and unvented thermal storage type electric water heaters. The specific safety specifications of prescribed products are set out in paragraph C1 1.1 of the guidance notes. Other household electrical products are non-prescribed products, which must comply with the requirements of the relevant international safety standards.
According to the Regulation, the Certificate of Safety Compliance of a prescribed product must be a CB test certificate, an endorsed certificate or a test report issued by a recognised certification body, or a declaration of conformity issued by a recognised manufacturer. The Certificate of Safety Compliance of a non-prescribed product must be a certificate or declaration issued by a recognised certification body or recognised manufacturer. In addition, a declaration of conformity supported by relevant certificates and/or test reports issued by the product manufacturer may also be accepted as a Certificate of Safety Compliance of that electrical product.
Electromagnetic Field Safety Standards
It is a requirement by the European Union (EU) that any household electrical product to be imported into the EU market must meet the specification that the electromagnetic field (EMF) generated by that household electrical product shall not produce radiation likely to cause danger to the general public. It has been decided following EMSD discussion with the trade that in addition to the relevant safety standards, household electrical products imported into Hong Kong on or after 1 January 2011 must also comply with the EMF safety standards. The applicable standard is IEC 62233 or EN 50366 or EN 62233, but these standards do not apply to electrical products such as audio, video and information technology equipment as well as luminaires.
LED Lamps Safety Standards
Recently, EMSD received enquiries from a number of suppliers concerning LED lamps safety standards. With reference to the guidelines issued by the relevant technical committee of IEC, the suggested applicable LED lamps safety standards for lamp caps like E14 and E27 are IEC 62560, IEC 60968, IEC 62031 and IEC 62471.
In order to enhance the professional standard of registered electrical workers (REWs) and promote a continuous learning culture in the electrical trade, EMSD, after discussing with the trade, will implement a Continuing Professional Development (CPD) Scheme for REWs starting from 2012. The scheme will make reference to the new Cable Colour Code (CCC) training scheme which has been implemented since 2007. REWs are required to complete the recognised CPD training courses or exercises each time they make their registration renewal application. The scope of training includes electricity legislation, electrical work safety, and technical knowledge in different fields, etc. EMSD will announce to all REWs the details of the scheme at a later time.
Representatives from the Fa Yuen Street Hawker Association, workers union, contractors' association, CLP, IVE and colleagues of EMSD in a group photo. In the early morning of 6 December 2010, a No. 3 alarm fire occurred at Fa Yuen Street, and several dozens of fixed pitch hawker stalls were burnt down. Relevant government departments took immediate action to handle the aftermath of the fire. To help the stall traders to re-establish their business as soon as possible, EMSD proactively contacted and coordinated the stall restoration work with the CLP Power Hong Kong Limited, the Hong Kong and Kowloon Electrical Engineering and Appliances Trade Workers Union, the Hong Kong Electrical Contractors' Association and the Hong Kong Institute of Vocational Education (IVE) (Haking Wong). Work commenced promptly on resuming the electricity supply, re-connecting wires, installing lightings and sockets for the affected stalls.
Under the concerted efforts of the participating parties who worked day and night, and even on holidays for the restoration work, the electricity supply and electrical installation work for all the affected stalls were completed before Christmas, so the stall traders could resume their business in time for the golden Christmas holiday. The Federation of Hong Kong, Kowloon and New Territories Hawkers Associations and the Fa Yuen Street Hawker Association subsequently wrote to express their appreciation to all parties who had assisted in the restoration work. This is a precious experience and has laid a solid foundation for the further cooperation between EMSD and trade associations in the future.
The 2009 edition of the Code of Practice for the Electricity (Wiring) Regulations (CoP) must be familiar to many as it has already been published for some time.
According to Code 1 of the CoP, electrical installations completed and connected to electricity supplies on or after 31 March 2011, including newly installed and altered electrical installations, must comply with the new requirements. That is why now when you carry out electrical work, you must follow the 2009 edition of the CoP. The CoP can be purchased at the Publications Sales Unit of the Information Services Department at Room 402, Murray Building, Garden Road, Central, or ordered by phone at 2537 1910, through the online Government Bookstore or by e-mail . The CoP can also be downloaded free of charge from the EMSD website.
The Electricity (Registration) Regulations requires that registered electrical workers (REWs) and contractors (RECs) should submit to EMSD applications for renewal of registration at least 1 month before, and no earlier than 4 months before, the expiry date of the current registration. All REWs and RECs are reminded again to submit their renewal applications within the above-mentioned period. Applications submitted after the expiry date of the current registration will be treated as new registration applications, and will be assessed in accordance with the prevailing statutory requirements. These include requiring REWs to possess recognised academic qualifications on electrical engineering and relevant electrical work experience. If an applicant does not possess the required academic qualifications and is thus unable to fulfil the registration requirements that apply, the application will be rejected regardless of the previous registration history of the applicant.
In addition, the renewal of registration will be effective from the date of approval. Any electrical worker or contractor who carries out electrical work or undertakes business as an electrical contractor during the period from the day after the expiry date of the certificate of registration to the day before the effective date of the renewal of registration commits an offence and shall be liable upon conviction to imprisonment for 6 months and a fine.
When carrying out PITC work for electrical installations, registered electrical workers (REWs) and contractors (RECs) should comply with the requirements set out in the 2009 edition of the Code of Practice for the Electricity (Wiring) Regulations. They should cut off the power supply of the electrical installations and apply suitable safety precautionary measures before carrying out the work. Furthermore, when carrying out PITC work for the main incoming circuit-breaker of the main switchboard, they should apply for temporary disconnection of power supply with the electricity company to ensure safety of the electrical workers and avoid causing damage to and impact on the power supply of the building in case of accident.
To enhance the standard of the PITC work for fixed electrical installations, EMSD has put in place the following "Standard Guidelines for the Periodic Inspection, Testing and Certification Work (WR2) for Fixed Electrical Installations" for compliance by the trade:
Video for Electrical Workers 2 - The 8 Steps in Periodic Inspection, Testing and Certification Work
To familiarize electrical workers more easily with the PITC work for low voltage fixed electrical installation, EMSD has produced a video entitled "Video for Electrical Workers 2 - The 8 Steps in Periodic Inspection, Testing and Certification Work" for their reference.
DVD copies of the video are available free of charge at the Customer Services Office on the ground floor of EMSD Headquarters (3 Kai Shing Street, Kowloon Bay, Kowloon) or offices of the Hong Kong and Kowloon Electrical Engineering and Appliances Trade Workers Union. It may also be downloaded at the following websites:
EMSD website:
Video for Electrical Workers
Following the first Safety Competition held in 2009, we will organise the second Safety Competition for Registered Electrical Workers with the trade to further strengthen work safety for the electrical workers and encourage the trade to actively implement work safety measures.
Enrolment to the competition will start in July this year. We will write to invite all registered electrical contractors and property management companies in the territory to participate by nominating their registered electrical workers. Details of the competition will be announced on EMSD website at a later stage. All trade practitioners are welcome to participate.
The Annual Technical Seminar jointly organised by EMSD, the Hong Kong and Kowloon Electrical Engineering and Appliances Trade Workers Union and the Hong Kong Electrical Contractors' Association was held on the night of 21 January 2011 at the Jockey Club Auditorium of the Hong Kong Polytechnic University. It was well-attended by nearly 1000 members of the electrical trade.
This year marks the 10th anniversary of the seminar. The theme of the seminar was "Collaborating to Build a Better Future-Ten Years On". Two engineers of EMSD and Mr TANG Sing-sum, Vice Principal of the Hong Kong Institute of Vocational Education (IVE) (Sha Tin) gave presentations on the Guidelines for Periodic Inspection, Testing and Certification Work, the Performance Monitoring Point System for RECs and REWs, and on How to Carry Out Secondary Injection Test for Protective Relays. The participants responded with great enthusiasm, showing great interest in the above-mentioned topics and actively participated in the discussion.
Members of the electrical trade who were unable to attend the above-mentioned seminar may go to the following EMSD website to browse the presentation materials of the topics covered in the seminar.
The seminar is enthusiastically attended by about 1000 members of the electrical trade.
The Director, Mr CHAN Hung-cheung JP, in a group photo on the stage with the representatives from EMSD and other co-organisers.
1. |
Apart from the basic safety requirements, which of the following electromagnetic standard applies to the domestic electrical products imported to Hong Kong starting from 1 January 2011? |
|
2. |
According to the Electrical Products (Safety) Regulations, which of the following electrical products is a non-prescribed product? |
|
3. |
According to the 2009 edition of the Code of Practice for the Electricity (Wiring) Regulations, within how many metres above finished floor level must all circuits supplying electrical equipment in the bathroom with exposed conductive parts be protected by one or more residual current device with a residual operating current not exceeding 30mA? |
|
4. |
According to the 2009 edition of the Code of Practice for the Electricity (Wiring) Regulations, with the exception of circuits exceeding 32A, Category 3 circuits, circuits supplying essential equipment which are not readily accessible to the general public, or circuits supplying life-support systems, for circuits supplying fixed equipment within the equipotential zone, within how many second(s) should disconnection occur by way of the earth fault loop impedance at every point of utilisation? |
|
5. |
According to the 2009 edition of the Code of Practice for the Electricity (Wiring) Regulations, to determine whether conductive parts such as metallic bathroom accessories, metallic windows or metallic door handles are extraneous conductive parts, a measurement should be made to obtain the insulation resistance between the conductive part and the main earthing terminal. For a typical single-phase supply system with a nominal supply voltage of 220V, at how many Ohm could the measured resistance be maintained, even under the worst conditions (e.g. high moisture), for the metallic part be considered as a non-extraneous conductive part? |
|
( Ans: 1C, 2B, 3A, 4B, 5C )
We look forward to receiving your valuable feedback about this newsletter for continuous improvement. Please complete the feedback form below and return it to our Electricity Legislation Division by post, fax or e-mail on or before 30 May 2011 (please refer to the contact information at the bottom of this page).
Electricity Legislation Division, EMSD, 3 Kai Shing Street, Kowloon, Hong Kong
1823
2895 4929